Since plastics are formed easily and can be formed to have various shapes easily, they are used widely for various purposes. For example, they are used preferably as containers to contain various beverages, edible oils, seasoning liquids, gel-like viscous foods such as yoghurt, as well as liquid detergents and pastes.
A container to contain a liquid content or a gel-like content is often required to prevent effectively the content from adhering and remaining on the inner surface of the container (non-adhesiveness of the content), or to discharge the content speedily from the container (slip-down property of the content).
Known methods for improving the non-adhesiveness and the slip-down property (hereinafter, these properties may be called slipperiness) include distributing hydrophobic fine particles on the surface to be in contact with the content, and covering the surface with a solid wax (see Patent Documents 1-3, for example).
That is, these known methods are to provide excellent slipperiness with respect to a moisture-containing content by applying hydrophobic fine particles or solid wax on the surface to be in contact with the content. In particular, when the hydrophobic fine particles are distributed on the surface, irregularities are provided on the surface to remarkably improve the slipperiness to the content. That is, when the content moves on the surface of the irregularities, the content moves in contact with air present among the irregularities. Since air has the highest water repellency, water repellency exhibited by the hydrophobic fine particles and the water repellency caused by the irregularities are combined with each other to considerably increase the slipperiness with respect to the content.